(svn r5723) - Move the declaration of DrawRoadDepotSprite() out of functions.h (but I'm not too happy with the new header)

- Use DiagDirection instead of plain int for the orientation of the depot graphics
- Rename the associated data tables with sprites to something more meaningful

road_cmd.h

@@ -0,0 +1,10 @@
+/* $Id$ */
+
+#ifndef ROAD_CMD_H
+#define ROAD_CMD_H
+
+#include "direction.h"
+
+void DrawRoadDepotSprite(int x, int y, DiagDirection dir);
+
+#endif